SIST EN 50530:2011
(Main)Overall efficiency of photovoltaic inverters
Overall efficiency of photovoltaic inverters
This European Standard provides a procedure for the measurement of the efficiency of the maximum power point tracking (MPPT) of inverters, which are used in grid-connected photovoltaic systems. In that case the inverter energizes a low voltage grid with rated AC voltage and rated frequency. Both the static and dynamic MPPT efficiency is considered. Based on the static MPPT efficiency and conversion efficiency the overall inverter efficiency is calculated. The dynamic MPPT efficiency is indicated separately.
Gesamtwirkungsgrad von Photovoltaik-Wechselrichtern
Rendement global des onduleurs photovoltaïques
La présente Norme Européenne fournit une procédure de mesure de l’efficacité de la conversion optimale d’énergie (MPPT – Maximum Power Point Tracking en anglais) des onduleurs, qui sont utilisés dans des systèmes photovoltaïques raccordés au réseau. Dans ce cas, l'onduleur alimente un réseau basse tension avec une tension alternative assignée et une fréquence assignée. L'efficacité de la MPPT tant statique que dynamique est prise en considération. L'efficacité globale de l'onduleur est calculée en fonction de l'efficacité de la MPPT statique et de l'efficacité de la conversion. L'efficacité de la MPPT dynamique est indiquée séparément.
Celovita učinkovitost fotonapetostnih razsmernikov
Ta evropski standard zagotavlja postopek za merjenje učinkovitosti sledenja maksimalni moči (MPPT) razsmernikov, ki se uporabljajo v omrežju povezanih fotonapetostnih sistemov. V tem primeru razsmernik napaja nizkonapetostno omrežje z nazivno izmenično napetostjo in nazivno frekvenco. Upoštevani sta statična in dinamična učinkovitost MPPT. Na osnovi statične učinkovitosti MPPT in učinkovitosti pretvorbe se izračuna celovita učinkovitost razsmernika. Dinamična učinkovitost MPPT je prikazana ločeno.
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Standards Content (Sample)
SLOVENSKI STANDARD
01-junij-2011
&HORYLWDXþLQNRYLWRVWIRWRQDSHWRVWQLKUD]VPHUQLNRY
Overall efficiency of photovoltaic inverters
Gesamtwirkungsgrad von Photovoltaik-Wechselrichtern
Rendement global des onduleurs photovoltaïques
Ta slovenski standard je istoveten z: EN 50530:2010
ICS:
27.160 6RQþQDHQHUJLMD Solar energy engineering
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN 50530
NORME EUROPÉENNE
April 2010
EUROPÄISCHE NORM
ICS 27.160
English version
Overall efficiency of grid connected photovoltaic inverters
Efficacité globale des onduleurs Gesamtwirkungsgrad von Photovoltaik-
photovoltaïques raccordés au réseau Wechselrichtern
This European Standard was approved by CENELEC on 2010-04-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Management Centre: Avenue Marnix 17, B - 1000 Brussels
© 2010 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50530:2010 E
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 82, Solar photovoltaic
energy systems. It was submitted to the Unique Acceptance Procedure and approved by CENELEC on
2010-04-01.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN and CENELEC shall not be held responsible for identifying any or all such patent
rights.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop) 2011-04-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow) 2013-04-01
__________
– 3 – EN 50530:2010
Contents
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
3.1 Inverter input (PV generator) . 5
3.2 Inverter output (grid) . 6
3.3 Measured quantities . 6
3.4 Calculated quantities . 7
3.5 Other definitions . 8
4 MPPT efficiency . 8
4.1 General description . 8
4.2 Test set-up . 9
4.3 Static MPPT efficiency . 9
4.4 Dynamic MPPT efficiency .11
4.5 Static power conversion efficiency .12
5 Calculation of the overall efficiency .14
Annex A (normative) Requirements on the measuring apparatus .15
A.1 PV generator simulator .15
A.2 AC power supply .16
Annex B (normative) Test conditions for dynamic MPPT efficiency .17
B.1 Test profiles .17
B.2 Test sequence with ramps 10 % - 50 % P .18
DCn
B.3 Test sequence with ramps 30 % - 100 % P .19
DCn
B.4 Start-up and shut-down test with slow ramps.19
B.5 Total test duration .20
Annex C (normative) Models of current/voltage characteristic of PV generator .21
C.1 1-Diode model .21
C.2 PV generator model for MPPT performance tests .22
Annex D (informative) Inverter efficiency .33
D.1 General / Introduction .33
D.2 Conversion efficiency .33
D.3 MPP-tracking efficiency .33
D.4 Overall efficiency η .34
t
D.5 Consequences .35
Bibliography .36
Figures
Figure 1 – Exemplary test set-up for MPPT efficiency measurements . 9
Figure B.1 – Test sequence for fluctuations between small and medium irradiation intensities . 17
Figure B.2 – Test sequence for fluctuations between medium and high irradiation intensities . 17
Figure B.3 – Test sequence for the start-up and shut-down test of grid connected inverters . 20
Figure C.1 – Irradiation-dependent U-I- and U-P characteristic of a c-Si PV generator . 25
Figure C.2 – Irradiation-dependent U-I- and U-P characteristic of a thin-film PV generator . 26
Tables
Table 1 – Test specifications for the static MPPT efficiency . 10
Table 2 – Test specification for the conversion efficiency . 13
Table A.1 – General requirements on the simulated I/V characteristic of the PV generator . 15
Table B.1 – Dynamic MPPT-Test 10 % ⇒ 50 % (valid for the evaluation of η ). 18
MPPTdyn
Table B.2 – Dynamic MPPT-Test 30 % ⇒ 100 % (valid for the evaluation of η ). 19
MPPTdyn
Table B.3 . 19
Table C.1 – Technology-dependent parameters . 22
Table C.2 – Technology-dependent parameters . 24
Table C.3 – MPP-values obtained with the cSi PV model . 24
Table C.4 – MPP-values obtained with the TF-PV mode . 27
– 5 – EN 50530:2010
1 Scope
This European Standard provides a procedure for the measurement of the efficiency of the maximum
power point tracking (MPPT) of inverters, which are used in grid-connected photovoltaic systems. In that
case the inverter energizes a low voltage grid with rated AC voltage and rated frequency. Both the static
and dynamic MPPT efficiency is considered.
Based on the static MPPT efficiency and conversion efficiency the overall inverter efficiency is calculated.
The dynamic MPPT efficiency is indicated separately.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN 61683, Photovoltaic systems – Power conditioners – Procedure for measuring efficiency (IEC 61683)
EN 50160, Voltage characteristics of electricity supplied by public distribution networks
EN 50524, Data sheet and name plate for photovoltaic inverters
CLC/TS 61836, Solar photovoltaic energy systems - Terms, definitions and symbols
(IEC/TS 61836:2007)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1 Inverter input (PV generator)
3.1.1
maximum input voltage (U )
DCmax
allowed maximum voltage at the inverter input
NOTE Exceeding of U may destroy the equipment under test.
DCmax
3.1.2
minimum input voltage (U )
DCmin
minimum input voltage for the inverter to energize the utility grid, independent of mode of operation
3.1.3
rated input voltage (U )
DC,r
input voltage specified by the manufacturer, to which other data sheet information refers
NOTE If this value is not specified by the manufacturer, V = (V + V )/2 shall be used.
dc,r mppmax mppmin
3.1.4
maximum MPP voltage (U )
MPPmax
maximum voltage at which the inverter can convert its rated power under MPPT conditions
NOTE If the specified value of the manufacturer for U is higher than 0,8 × U , the measurement must be performed with
MPPmax DCmax
U = 0,8 × U .
MPPmax DCmax
3.1.5
minimum MPP voltage (U )
MPPmin
minimum voltage at which the inverter can convert its rated power under MPPT conditions
NOTE The actual minimum MPP voltage may depend on the grid voltage level.
3.1.6
rated input power (P )
DC,r
rated input power of the inverter, which can be converted under continuous operating conditions
NOTE If this value is not specified by the manufacturer, it can be defined as P = P / η , in which η is the conversion
DC,r AC,r conv,r conv,r
efficiency at rated DC voltage.
3.1.7
maximum input current (I )
DC,max
maximum input current of the inverter under continuous operating conditions
NOTE At inverters with several independent inputs, this value may depend on the chosen input configuration.
3.2 Inverter output (grid)
3.2.1
rated grid voltage (U )
AC,r
utility grid voltage to which other data sheet information refers
3.2.2
rated power (P )
AC,r
active power the inverter can deliver in continuous operation
3.3 Measured quantities
3.3.1
PV simulator MPP-Power (P )
MPP, PVS
MPP power provided by the PV simulator
3.3.2
input power (P )
DC
measured input power of the device under test
3.3.3
PV simulator MPP voltage (U )
MPP, PVS
MPP voltage provided by the PV simulator
3.3.4
input voltage (U )
DC
measured input voltage of the device under test
3.3.5
PV simulator MPP current (I )
MPP, PVS
MPP current provided by the PV simulator
3.3.6
input current (I )
DC
measured input current of the device under test
3.3.7
output power (P )
AC
measured AC output power of the device under test
– 7 – EN 50530:2010
3.3.8
output voltage (U )
AC
measured AC voltage
3.3.9
output current (I )
AC
measured AC output current of the device under test
3.4 Calculated quantities
3.4.1
MPPT efficiency, energetic (η )
MPPT
ratio of the energy drawn by the device under test within a defined measuring period T to the energy
M
provided theoretically by the PV simulator in the maximum power point (MPP):
T
M
p ()td⋅t
DC
∫
η= (1)
MPPT T
M
p ()td⋅t
MPP
∫
where
p (t) instantaneous value of the power drawn by the device under test;
DC
p (t) instantaneous value of the MPP power provided theoretically by the PV simulator
MPP
3.4.2
conversion efficiency, energetic (η )
conv
ratio of the energy delivered by the device under test at the AC terminal within a defined measuring
period T to the energy accepted by the device under test at the DC terminal:
M
T
M
p ()td⋅t
AC
∫
η= (2)
conv
T
M
...
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